TTL or "Through-The-Lens" flash metering means the strobe interprets information from the camera to control flash duration and properly expose an image. TTL may be accomplished directly through electrical signals from the camera, or indirectly through watching the behavior of the camera's built-in flash.

Circuitry built into this housing allows the camera to communicate directly with compatible underwater strobes (see Strobe Compatibility section below). When connected via this circuitry, the camera learns that an external flash is attached and is able to more accurately adjust exposure by knowing this. The camera's flash will not fire, eliminating the shutter lag associated with waiting for the camera's flash to recycle.

The Ikelite-style electrical bulkhead is widely recognized as the most reliable waterproof strobe sync connection available. In order to communicate with the camera, compatible Ikelite DS strobes must be connected to the housing's electrical bulkhead using a single or dual TTL sync cord.

Non-Ikelite strobes may be connected to this bulkhead using a compatible sync cord, however the housing's circuitry will not receive power and the strobes will operate in manual exposure modes only.

Whether in TTL or manual exposure, use of an electrical sync cord eliminates the issues of signal interference, inconsistent exposure due to weak fiber optic transmission, and false triggering caused by light rays bouncing off the water's surface or your buddy's flash going off. Sync cords are comparably priced to fiber optic cords and are equally durable.

The housing port is designed to accept color filter, wide angle, and macro options for 3.9-inch diameter ports. Light is absorbed very quickly as it passes through water. A subject will look darker, less colorful and somewhat grainy when viewed through even a few feet of water. The addition of a compatible wide angle accessory expands the camera's field of view underwater, providing the opportunity to get as close as possible to the subject and reduce the amount of water light passes through. The results speak for themselves - photos with the best color, exposure and clarity possible.

Simply close the two stainless steel locking lid snaps, and see the o-ring form a solid black, watertight seal. Large, ergonomic controls provide access to all important camera functions including front and rear dials. An included tray with soft-grip handle provides comfortable handling underwater and our signature quick release attachment system for lighting accessories.

Ikelite products are designed, built and tested in the USA. We use locally sourced, top-grade materials. Our housings are built by hand and individually tested for fit, function and waterproof integrity. We back our products with over 50 years of experience and service within the dive industry.